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1、NATIONAL SCIENCE BOARDSCIENCE&ENGINEERING INDICATORS 2024R&DPublications Output:U.S.Trends and International ComparisonsNSB-2023-33December 11,2023This publication is part of the 2024 edition of the Science and Engineering Indicators(Indicators)suite of reports.Indicators is prepared under the guida

2、nce of the National Science Board by the National Science Foundations National Center for Science and Engineering Statistics.The Indicators suite consists of a summary report called The State of U.S.Science and Engineering,more-detailed thematic reports with supporting data,and a data tool that prov

3、ides state-level indicators.National Science Board|Science&Engineering Indicators|NSB-2023-332National Science Board|Science&Engineering Indicators|NSB-2023-333Table of Contents 7Executive Summary 9Introduction 9Bibliometric Data Preliminaries 10Publication Output by Region,Country,or Economy and by

4、 Scientific Field 10Output by Region,Country,or Economy 14Output by Scientific Field 23Output and Open Access 25Impact of Published Research 25Impact by Region,Country,or Economy 29Impact and Open Access 31International Collaboration and Citations 31International Collaboration Patterns 40Internation

5、al Citation Patterns 45Conclusion 46Glossary 46Definitions 47Key to Acronyms and Abbreviations 49References 52Notes 54Acknowledgments and Citation 54Acknowledgments 54Citation 55Technical Appendix 55DataNational Science Board|Science&Engineering Indicators|NSB-2023-334 60Fractional and Whole Countin

6、g 60Network Analysis of Artificial Intelligence Papers 61Key to Acronyms and Abbreviations 62References 64Contact Us 64Report Authors 64NCSESList of Sidebars 36Artificial Intelligence Publication Output and International Collaboration 19Using Funding Acknowledgments to Track Federally Funded Researc

7、h Over TimeList of TablesPBS-1S&E publications in all fields for 15 largest producing regions,countries,or economies:2012 and 2022 13PBS-2Relative citation index for 15 largest producing regions,countries,or economies:2020 42PBS-AU.S.S&E publications,by U.S.federal funding status and field:201822 22

8、List of FiguresPBS-1S&E publications,by income group:200322 10PBS-2S&E publications for 10 leading regions,countries,or economies:2022 11PBS-3S&E publications,by selected region,country,or economy and rest of world:200322 14PBS-4Distribution of national S&E research portfolios across scientific fiel

9、ds,by selected region,country,or economy:2022 15PBS-5U.S.S&E publication portfolio,by field of science:2022 16PBS-6S&E publication portfolio from China,by field of science:2022 17PBS-7Index of U.S.publications,by field:201022 19PBS-8S&E publications,by publication access type:200322 24PBS-9S&E publi

10、cations in the top 1%most-cited journal articles as a share of all S&E journal articles,by selected region,country,or economy:200620 26PBS-10S&E publications in the top 1%most-cited journal articles as a share of all journal articles for selected S&E fields,by selected region,country,or economy:2020

11、 28PBS-11S&E publications in the top 1%most-cited journal articles as a share of all articles,by publication access type:200620 30PBS-12International coauthorship of S&E publications for the 15 largest producing regions,countries,or economies of S&E publications:2022 32National Science Board|Science

12、&Engineering Indicators|NSB-2023-335PBS-13Selected leading region,countries,or economies with publications with international coauthors:200322 33PBS-14U.S.international S&E publications with coauthor(s)from the United Kingdom and Asian countries:Selected years,200422 34PBS-15Relative international c

13、ollaboration index of selected large-producing regions,countries,or economies with the United States:2003 and 2022 35PBS-16U.S.domestic relative citation index across fields:2022 43PBS-AU.S.S&E publications with and without acknowledgments of U.S.federal funding:200322 21PBS-BAI collaboration networ

14、k,by region,country,or economy:20032022 37PBS-CAI index of collaboration,by region,country,or economy pairs:20032022 39SAPBS-1 Filtered and unfiltered publications in Scopus,by year:200822 56SAPBS-2 Impact of removing low-quality publications from Scopus,by selected region,country,or economy:200822

15、57SAPBS-3 Impact of removing low-quality publications from Scopus,by field of science:200822 58National Science Board|Science&Engineering Indicators|NSB-2023-336National Science Board|Science&Engineering Indicators|NSB-2023-337Executive SummaryKey takeaways:The primary method of disseminating resear

16、ch findings is through publication of peer-reviewed journal articles and conference proceedings(i.e.,publication output).Data on publication output indicate a continued increase in global research activity,a growth in the proliferation and impact of some categories of OA research,and an internationa

17、lly connected research ecosystem.Global publication output reached 3.3 million articles in 2022,based on data from the Scopus database of S&E publications.The regions,countries,or economies with the largest volume of S&E publications in 2022 were China,with 27%of global output,and the United States,

18、with 14%.From 2012 to 2022,the global yearly publication total grew by 59%.In terms of growth for these two largest producers,China and the United States had noticeably different expansion in their levels of overall production(growing by 173%and 6%,respectively).Beyond differences at the level of re

19、gion,country,or economy,the number of OA publications has increased dramatically in the last 10 years.In 2022,nearly 1.6 million articles were OA(classified in one of four OA categories),compared with about 1.5 million traditional closed-access journal articles.Just 10 years prior,OA articles accoun

20、ted for around a third of all articles with a known access status.This growth is also clear with respect to impact,where OA research as a whole has a higher proportion of highly cited articles relative to the size of OA scholarship.When an article is cited by a high number of subsequent articles by

21、other authors,it is deemed to have exceptional scientific impact.Analyzing the distribution of highly cited articles based on the authors locations,the United States has a long-standing record of producing a disproportionate share of such articles,although its share has decreased in recent years.Chi

22、nas share of those articles grew consistently over the past 20 years,and its scientific impact is on par with that of the EU-27.That impact varies by scientific discipline.In 2020,publications by authors in the United States in materials science,geosciences,and physics had relatively higher scientif

23、ic impact than those in other fields.For publications by authors in China for the same year,those in the social sciences tended to have higher scientific impact than those in any other field.The United States remains a highly influential nation in science and engineering(S&E)research,as measured by

24、the volume of peer-reviewed scholarly publications and the rate of citations to those publications.In 2022,China remained the largest producer of publications,followed by the United States,then by India.Chinas top scientific field in terms of number of articles produced was engineering(25%of all pub

25、lications),whereas the top field in the United States was health sciences(37%),and Indias top field was computer and information sciences(21%).Analysis of funding acknowledgments shows that from 2018 to 2022,the scientific fields most frequently acknowledging federal funding are chemistry,biological

26、 and biomedical sciences,astronomy and astrophysics,and physics.The United States,the European Union(EU-27),and China currently produce a high number of highly cited articles,relative to their overall production.Open access(OA)has become an increasingly important feature of the publication landscape

27、,in terms of output and impact,as shown by the growth of fully OA articles.International collaborations with U.S.authors of S&E publications have increased over the last 15 years,and China is the most frequent U.S.partner.International collaboration in the fast-growing field of artificial intelligen

28、ce helps show an important research network and the most important collaborations in terms of absolute and relative size.National Science Board|Science&Engineering Indicators|NSB-2023-338International collaborations continue to grow in their share of global scientific publications.From 2012 to 2022,

29、the share of articles from authors affiliated with institutions in multiple regions,countries,or economies increased by 19%.In 2022,the United States was involved in a high number of international collaborations(40%of U.S.articles produced included an international coauthor).Other top producers like

30、 China(19%),India(24%),and the United Kingdom(67%)varied in the concentration of international collaborations among their respective total outputs.National Science Board|Science&Engineering Indicators|NSB-2023-339IntroductionResearch publications and presentations at conferences represent the main m

31、echanisms for disseminating research findings.Presentations appear in the published research literature in conference proceedings.Published literature is an indicator of scientific activity and global research partnerships.Additionally,analysis of how published literature is cited provides insight i

32、nto the impact of research output.Scientific publications serve as a key linkage enabling public uses of scientific output(Yin et al.2022).This report presents data on research publication output by region,country,or economy and scientific field;impact measures;and international collaboration.The fi

33、rst section examines comparative region,country,or economy data on publication output across science and engineering(S&E)fields and includes a sidebar on federal funding acknowledgments.The second section provides an analysis of scientific impact as measured by bibliographic citations in research pu

34、blications.The third section focuses on collaboration among researchers in the United States and those in other regions,countries,or economies through examining coauthoring and citation patterns.This section also includes a sidebar on the artificial intelligence(AI)publication output and collaborati

35、on network.Bibliometric Data PreliminariesThis report analyzes S&E publications and citations using bibliometric data in Scopus,a database of scientific literature with English-language titles and abstracts(Science-Metrix 2021a).Because research activities are complex and multifaceted processes,the

36、knowledge and social benefits that they produce are difficult to measure directly.Bibliometric data,including publications and citations,provide invaluable indicators of research output due to their ubiquity across regions,countries,or economies and time.Nonetheless,bibliometric analyses of publicat

37、ion and citation data remain proxy measures for the knowledge and social benefits produced by research activities,so they carry certain limitations.Publications themselves may represent differing“amounts”of research output because differences in field conventions or incentive structures may result i

38、n more or fewer publications covering novel research findings.In addition,publications do not represent all types of research products,such as data sets(Franzoni,Scellato,and Stephan 2011;Sugimoto and Larivire 2018).This report analyzes nearly 44 million English-language articles published from 2003

39、 to 2022.The analysis included papers published in conference proceedings and research articles published in peer-reviewed scientific and technical journals(collectively referred to as articles).The analysis excluded editorials,errata,letters,and other materials that do not typically present new sci

40、entific data,theories,methods,apparatuses,or experiments.The analysis also excluded working papers and preprints,which typically have not yet been peer reviewed,and articles published in journals that lack substantive peer review,sometimes referred to as predatory journals(Grudniewicz et al.2019).Ev

41、en with robust coverage and filtering,bibliometric data may retain biases or gaps in coverage,including a bias toward English-speaking regions,countries,or economies.In terms of interpretability,longer-term trends are the best way to view publications-related data.Year-to-year differences may be due

42、 to the process by which the information is indexed in Scopus.Additional details regarding document selection,limitations,and sources of bias are available in the Technical Appendix.Information about how research was producedsuch as the field;region,country,or economy of origin;and collaboration may

43、 also be inferred from bibliometric data.For example,author affiliation data were used for determining publication output by region,country,or economy through fractional counting and international collaborations through whole counting.The supplemental tables include calculations using both whole and

44、 fractional counting for the various indicators to illustrate the difference in results.Articles were categorized by S&E fields corresponding to the 14 fields of science in the National Center for Science and Engineering Statistics(NCSES)Taxonomy of Disciplines(TOD)(Science-Metrix 2019).Additional d

45、etails regarding fractional and whole counting,field categorization,and limitations are available in the Technical Appendix.National Science Board|Science&Engineering Indicators|NSB-2023-3310Publication yearNumber of articlesHigh-income regions,countries,or economiesUpper-middle-income regions,count

46、ries,or economiesLower-middle-income regions,countries,or economies200320042005200620072008200920102011201220132014201520162017201820192020202120220500,0001,000,0001,500,0002,000,000Publication Output by Region,Country,or Economy and by Scientific FieldThis section of the report outlines trends over

47、 time in publication output across regions,countries,or economies and by fields of science.This section also provides insights into the research contributions of different regions,countries,or economies and how the focus of their scientific publications has changed over time.In addition,the section

48、highlights variations in the distribution of publications across scientific fields for different regions,countries,or economies and examines trends over time in closed-access and open-access(OA)publications.This section also summarizes federal funding acknowledgments as a source of data to shed ligh

49、t on published research that received federal funding.(See sidebar Using Funding Acknowledgments to Track Federally Funded Research Over Time.)Output by Region,Country,or EconomyTotal worldwide S&E publication output reached 3.3 million articles in 2022,based on entries in the Scopus database.1 Appr

50、oximately 86%of publications in 2022 came from regions,countries,or economies with high-income and upper-middle-income economies(Figure PBS-1).The number of publications from all income-level groups grew between 2003 and 2022(Table SPBS-2).Also,the number of publications from upper-middle-income eco

51、nomies grew more quickly than the number from high-income economies during the more recent period between 2010 and 2022.Figure PBS-1S&E publications,by income group:200322Note(s):Article counts refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields

52、from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles produced by authors from different r

53、egions,countries,or economies,each region,country,or economy receives fractional credit on the basis of the proportion of its participating authors).Data are not directly comparable with data from Science and Engineering Indicators 2022;see the Technical Appendix for information on data filters.Low-

54、income National Science Board|Science&Engineering Indicators|NSB-2023-3311Region,country,or economyNumber of articlesChinaUnited StatesIndiaGermanyUnited KingdomJapanItalyRussiaSouth KoreaCanada01,000,000250,000500,000750,000regions,countries,or economies are not included in this figure because of t

55、heir low publication output.Data by region,country,or economy and income group are available in Table SPBS-2.Regions,countries,or economies are allocated to income groups based on World Bank data,using their current designation.For example,all of Chinas publications from 2003 to 2022 are counted as

56、part of the upper-middle-income category because that is Chinas current designation.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023;World Bank Country and Lending Groups,accessed May 2023.Science and E

57、ngineering IndicatorsIn 2022,six regions,countries,or economies each produced more than 100,000 articles:China,the United States,India,Germany,the United Kingdom,and Japan.Together,these leading regions,countries,or economies accounted for over 50%of the worldwide total in 2022(Figure PBS-2;Table PB

58、S-1).2 In absolute numbers,the growth in worldwide annual publication output(from 2.0 million in 2010 to 3.3 million in 2022)was driven in particular by two countries:China(42%of additional publications during that period)and India(11%)together accounted for more than half of that increase in public

59、ations(Figure PBS-3).Russia,South Korea,Iran,and Brazil made notable contributions to the growth in the number of publications from the rest of the world from 2010 to 2022(Figure PBS-3;Table SPBS-2).Generally,the set of the top 15 producers of S&E articles was the same each year between 2010 and 202

60、2,with the exception of Iran replacing Taiwan in the top 15 beginning in 2014(Table PBS-1;Table SPBS-2).Figure PBS-2S&E publications for 10 leading regions,countries,or economies:2022Note(s):Article counts refer to publications from a selection of conference proceedings and peer-reviewed journals in

61、 S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles produced by authors from

62、 different regions,countries,or economies,each region,country,or economy receives fractional credit on the basis of the proportion of its participating authors).Data by all countries,regions,and economies are available in Table SPBS-2.National Science Board|Science&Engineering Indicators|NSB-2023-33

63、12Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Board|Science&Engineering Indicators|NSB-2023-3313Table PBS-1S&E publications in all fields for 15 l

64、argest producing regions,countries,or economies:2012 and 2022(Number and percent)RankRegion,country,or economy201220222022 world total(%)naWorld2,105,1573,344,037na1China329,067898,94926.882United States430,164457,33513.683India78,135207,3906.204Germany105,639113,9763.415United Kingdom98,685105,5843

65、.166Japan109,040103,7233.107Italy64,13190,5862.718Russia36,53284,2522.529South Korea56,10176,9362.3010Canada59,76269,0522.0611Spain54,68067,1002.0112Brazil48,16667,0312.0013France72,43165,8881.9714Australia46,72862,3051.8615Iran31,46260,9401.82na=not applicable.Note(s):The regions,countries,or econo

66、mies are ranked based on the 2022 total.Article counts refer to publications from conference proceedings and peer-reviewed journal articles in S&E and indexed in Scopus(see Technical Appendix for more details).Articles are classified by their year of publication and are assigned to a region,country,

67、or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles from multiple regions,countries,or economies,each region,country,or economy receives fractional credit on the basis of the proportion of i

68、ts participating authors).Detail may not add to total because of regions,countries,or economies that are not shown.Proportions are based on the world total excluding unclassified addresses(data not presented).Details and other regions,countries,or economies are available in Table SPBS-2.Source(s):Na

69、tional Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Board|Science&Engineering Indicators|NSB-2023-3314Publication yearNumber of articlesWorldUnited StatesGermanyUnite

70、d KingdomChinaIndiaJapanRest of world2003200420052006200720082009201020112012201320142015201620172018201920202021202201,000,0002,000,0003,000,0004,000,000Figure PBS-3S&E publications,by selected region,country,or economy and rest of world:200322Note(s):Article counts refer to publications from a sel

71、ection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fra

72、ctional count basis(i.e.,for articles produced by authors from different countries,each country receives fractional credit on the basis of the proportion of its participating authors).Data for all regions,countries,and economies are available in Table SPBS-2.Source(s):National Center for Science and

73、 Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsThe U.S.trend of moderate but increasing publication output varied by state.The National Science Boards(NSBs)State Data Tool(https:/ncses.nsf.gov/indicators/sta

74、tes/)provides state-level data based on each states doctorate population and research and development(R&D)funding.Indicators include academic S&E article output per 1,000 science,engineering,and health doctorate holders in academia(NSB 2021a)and academic S&E article output per$1 million in academic

75、S&E R&D funding(NSB 2021b).Output by Scientific FieldThe distribution of publications by field of science across region,country,or economy may indicate research priorities and capabilities.Health sciences was the field of science in which most articles were published in 2022,representing almost a qu

76、arter of all publications(Table SPBS-2 and Table SPBS-10).Other fields with large numbers of publications included engineering(17%of publications in 2022),biological and biomedical sciences(13%),and social sciences(5%)(Table National Science Board|Science&Engineering Indicators|NSB-2023-3315Region,c

77、ountry,or economyPercent of S&E publicationsHealth sciencesBiological and biomedical sciencesEngineeringComputer and information sciencesPhysicsChemistrySocial sciencesMaterials scienceOtherUnited StatesEU-27JapanChinaIndia0102030405060708090100SPBS-2,Table SPBS-5,Table SPBS-8,and Table SPBS-16).In

78、the United States,the European Union(EU-27),and Japan,health sciences publication output in 2022 far exceeded that of any other field.3 Meanwhile,of the other top producers,publications from China were most highly concentrated in engineering(25%),and publications from India were published predominan

79、tly in computer and information sciences(21%)(Figure PBS-4).Figure PBS-4Distribution of national S&E research portfolios across scientific fields,by selected region,country,or economy:2022EU-27=European Union.Note(s):Articles refer to publications from a selection of conference proceedings and peer-

80、reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles from

81、 multiple countries,each country receives fractional credit on the basis of the proportion of its participating authors).See Table SPBS-1 for countries included in the EU;beginning in 2020,the United Kingdom was no longer a member of the EU.See Table SPBS-3 through Table SPBS-16 for data on all regi

82、ons,countries,and economies by each S&E field.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsFields within life sciences were dominant in the United States in 2022,wi

83、th more than half of all U.S.publications in health sciences(37%)or biological and biomedical sciences(14%)(Figure PBS-5).There were fewer U.S.publications in engineering(11%),computer and information sciences(7%),and physics(5%).In comparison with the United States,China had a stronger focus on pub

84、lications in engineering and in the physical sciences and information sciences.In 2022,25%of Chinas publications were in engineering,11%were in computer and information sciences,and 9%were in physics(Figure PBS-6).Compared with the United States,China had a lower percentage of its publications in he

85、alth sciences(14%)and biological and biomedical sciences(12%).In 2022,China also had a much lower percentage of its publications in social sciences(1%)when compared with the United States(8%).National Science Board|Science&Engineering Indicators|NSB-2023-3316PercentFigure PBS-5U.S.S&E publication po

86、rtfolio,by field of science:2022Note(s):Articles refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutiona

87、l address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles from multiple countries,each country receives fractional credit on the basis of the proportion of its participating authors).See Table SPBS-3 through Table SPBS-16 for data on all r

88、egions,countries,and economies by each S&E field.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Board|Science&Engineering Indicators|NSB-2023-3317Per

89、centFigure PBS-6S&E publication portfolio from China,by field of science:2022Note(s):Articles refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,countr

90、y,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles from multiple countries,each country receives fractional credit on the basis of the proportion of its participating authors).See Table S

91、PBS-3 through Table SPBS-16 for data on all regions,countries,and economies and by each S&E field.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Boar

92、d|Science&Engineering Indicators|NSB-2023-3318All the leading regions,countries,or economies saw an increase in their output of health sciences publications between 2010 and 2022.This increase is to be expected,given the context of increasing publication rates in general over that period,with overal

93、l number of publications increasing by 71%(Table SPBS-2),while publications in health sciences increased by 66%(Table SPBS-10).Russia had the highest relative growth rate among the 20 leading regions,countries,or economies in health sciences,increasing its publication output by almost 450%between 20

94、10 and 2022(Table SPBS-10).China and Iran each increased their output of health sciences publications by more than 250%over this period,while Indias health sciences publication output increased by more than 180%.The United States increased its output of health sciences publications by 32%over this p

95、eriod,while Germany,France,the United Kingdom,and Japan had the smallest increases,each with less than 20%.Leading regions,countries,or economies also saw increases in engineering publications.The fastest growing between 2010 and 2022 were India(up 378%)and Russia(up 230%)(Table SPBS-8).China increa

96、sed its output of engineering publications by 176%from 2010 to 2022,while France,the United States,and Japan all saw declines in newly published engineering articles per year over this period(3%,13%,and 26%,respectively).In the United States,publication output varied from that of other regions,count

97、ries,or economies with respect to scientific fields.Of the fields not already mentioned,the fastest growing from 2010 to 2022 were psychology(up 39%from 2010 to 2022)and the social sciences(up 38%)(Figure PBS-7).Meanwhile,fields with the largest decreases in U.S.publications included physics(down 31

98、%from 2010 to 2022)and materials science(down 16%).National Science Board|Science&Engineering Indicators|NSB-2023-3319YearIndex base:2010=100Social sciencesPsychologyHealth sciencesMathematics and statisticsNatural resources andconservationAgricultural sciencesBiological and biomedical sciencesChemi

99、stryAstronomy and astrophysicsGeosciences,atmosphericsciences,and ocean sciencesComputer and informationsciencesMaterials scienceEngineeringPhysics201020112012201320142015201620172018201920202021202205060708090100110120130140150Figure PBS-7Index of U.S.publications,by field:201022Note(s):Articles re

100、fer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.

101、Articles are credited on a fractional count basis(i.e.,for articles from multiple countries,each country receives fractional credit on the basis of the proportion of its participating authors).See Table SPBS-3 through Table SPBS-16 for data on all regions,countries,and economies by each S&E field.So

102、urce(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsSIDEBAR USING FUNDING ACKNOWLEDGMENTS TO TRACK FEDERALLY FUNDED RESEARCH OVER TIMEUsing Funding Acknowledgments to Track

103、Federally Funded Research Over TimeNational Science Board|Science&Engineering Indicators|NSB-2023-3320Federally funded research is an important component of the research ecosystem and is often envisioned as a means of supporting science performed for public benefit that may not otherwise be motivate

104、d by commercial interest(Bornmann 2013;Stephan 2012;Yin et al.2022).Federal research funding supports applied and basic research(see Indicators 2022 report“2022 Research and Development:U.S.Trends and International Comparisons”)and has long been linked to successful expansions in scientific producti

105、onthrough the increased productivity and impact of individual researchers and laboratories(Ebadi and Schiffauerova 2016)and the national scale(Leydesdorff and Wagner 2009).This sidebar explores funding acknowledgments,as recorded in Scopus,as an emerging source to help illustrate the extent to which

106、 published research is supported by federal agencies and the trends in federally funded research.Specifically,the share of published research acknowledging support by federal funding was highest in chemistry and smaller in other fields,such as the social sciences(Table PBS-A).These differences may b

107、e driven by factors such as the resource costs to conduct research and by field differences,such as the overall frequency of publication,team size,and cultural differences among the disciplines.The time period analyzed in this sidebar is 201822,unless otherwise indicated.Funding acknowledgments can

108、shed light on the ability and priorities of federal funding to support discovery as measured by peer-reviewed journal articles and conference proceedings.However,some benefits and limitations of this emerging data source are important to highlight so as to accurately interpret these trends.Each peer

109、-reviewed journal article and conference proceeding in the Scopus database includes a field for funding acknowledgments that are extracted by algorithmic(software)means.In some cases where the acknowledgments field is incomplete,funding information from agencies is also used to identify funded publi

110、cations in Scopus.Using this field,it is possible to observe the conversion of federal funds to published research outputs,but a direct linkage between funding inputs and published discoveries remains challenging.First,extraction of this information into a structured field is a relatively new effort

111、 and is most complete for the most recent 4 years.Figure SPBS-1 shows how funding acknowledgment sections have grown in coverage since 2003 and that funding information was indexed for 68%of all publications in 2022.*Many factors may have contributed to this growth in addition to improved extraction

112、,including increasing pressure and requirements from funders to include funding acknowledgments,standardization of acknowledgment language,and incentives to demonstrate high publication outputbecause future funding is tied to past conversion of funds into publicationswhile receiving funding.Last,thi

113、s inquiry helps explore research that acknowledges any federal funding but does not only account for publications that source all their funding from a single source.In practice,a publication may be generated using funding from multiple sources within the federal government,or from additional sources

114、 in state government,local government,or the private sector.National Science Board|Science&Engineering Indicators|NSB-2023-3321YearNumber of articlesU.S.publications without acknowledgment of federal fundingU.S.publications with acknowledgment of federal funding20032004200520062007200820092010201120

115、1220132014201520162017201820192020202120220100,000200,000300,000400,000500,000600,000700,000Figure PBS-AU.S.S&E publications with and without acknowledgments of U.S.federal funding:200322Note(s):Articles are classified by their year of publication and are assigned to a region,country,or economy on t

116、he basis of the institutional address(es)of the author(s)listed in the article.Whole counting is used.An article is considered to be federally funded if the funding information tied with the publication record in Scopus links it with one of the U.S.federal agencies.Not all Scopus publications have f

117、unding information available,and coverage has evolved with time.For more information,see Figure SPBS-1.For a breakdown of federally funded papers by funding agency,see Table SPBS-90.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation

118、database,accessed April 2023.Science and Engineering IndicatorsFigure PBS-A tracks the growth of federally funded publications relative to the total research production in the United States.Other than a small downturn from 2021 to 2022,every year has seen an increase from the previous year in the nu

119、mber of publications that acknowledge funding support from federal agencies.The most comprehensive data from the past 4 years show variation among subject areas in the percentage of publications that acknowledge federal support.Table PBS-A shows number and share of publications appearing between 201

120、8 and 2022 that acknowledged funding from federal sources and those acknowledging funding from other sources.During this time,more than 50%of publications in the following subject fields acknowledged federal funding support:chemistry(55%of publications),National Science Board|Science&Engineering Ind

121、icators|NSB-2023-3322biological and biomedical sciences(53%),astronomy and astrophysics(53%),and physics(52%).Only two subject areas have less than 30%of publications with federal funding acknowledged:agricultural sciences(28%),and social sciences(15%).Otherwise,all other fields had between 30%and 5

122、0%of their publications acknowledging federal funding.Table PBS-AU.S.S&E publications,by U.S.federal funding status and field:201822(Number and percent)FieldU.S.publications(total)U.S.publications(federally funded)Percentage of federally funded publicationsU.S.publications(other funding)Percentage o

123、f publications acknowledging funding from another sourceHealth sciences1,004,671318,83831.7239,60623.8Biological and biomedical sciences447,843237,47253.0151,51133.8Engineering356,520128,10635.967,69219.0Computer and information sciences235,76579,21833.629,52812.5Social sciences202,90029,69414.630,2

124、8214.9Physics191,70098,71651.539,48020.6Geosciences,atmospheric sciences,and ocean sciences109,18349,64745.531,72829.1Psychology107,48034,85332.423,67822.0Chemistry103,21756,36154.630,79729.8Mathematics and statistics63,73327,63443.412,64419.8Natural resources and conservation52,01017,97934.614,3112

125、7.5Materials science42,61019,85946.610,04623.6Agricultural sciences42,41911,70127.610,38424.5Astronomy and astrophysics34,35818,05052.58,38224.4Note(s):Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of

126、 the author(s)listed in the article.Whole counting is used.An article is considered to be federally funded if the funding information tied with the publication record in Scopus links it with one of the U.S.federal agencies.Not all Scopus publications have funding information available,and coverage h

127、as evolved with time.For more information,see Figure SPBS-1.For a breakdown of federally funded papers by funding agency,see Table SPBS-90.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and En

128、gineering IndicatorsIn conclusion,federal funding plays an important role in the current research environment in the United States.Of the 606,144 articles published in journals and conference proceedings in 2022,35%acknowledged support from federal agencies(Figure PBS-A).Ultimately,acknowledgment of

129、 federal funding can help show trends in the conversion of grants into published research over time and show variation at the subject or field level.National Science Board|Science&Engineering Indicators|NSB-2023-3323*Missing data in funding fields in a Scopus entry may mean that the research did not

130、 receive funding,the authors did not cite any funding despite receiving it,or the algorithm was unable to extract the acknowledgment.Of the articles from 2003 that had an entry for funding acknowledgment(27%had text in the funding field in Scopus),around 76%acknowledged a federal funding source.Comp

131、aratively,of the publications in 2022 with indexed funding information(68%),52%acknowledged a federal source.The growth of coverage of funding not being tied to federal funding acknowledgments provides evidence that the data source has become more dependable over time.Data for the percentage of publ

132、ications with indexed funding sources by year and field can be found in Figure SPBS-1.Table SPBS-90 displays the number of articles and conference proceedings acknowledging federal funding at the agency level and sub-agency level.These counts represent the number of supported articles as acknowledge

133、d and attributed in Scopus from 2003 to 2022.Output and Open AccessThere is growing support for the availability of S&E publications through OA sources among government and private funders,institutions,and scientists themselves.Some of these funders have imposed requirements on their grantees to pub

134、lish their research results in OA journals.In the United States,the Office of Science and Technology Policy announced that all federal agencies should update their public access policies as soon as possible to ensure that results of their funded research are publicly available,with full implementati

135、on of these policies by the end of 2025(Brainard and Kaiser 2022).Meanwhile,restricted access to scientific literature may impede researchers ability to stay informed(Larivire and Sugimoto 2018;Piwowar et al.2018).As alternatives to traditional closed-access journals(where readers must subscribe to

136、gain access or pay per article),articles may be made OA through several avenues,with different levels of availability and durability.There are four commonly defined types of OA:Gold,Hybrid,Bronze,and Green.Gold OA denotes articles published in journals that are entirely OA as a matter of journal pol

137、icy.Hybrid OA denotes articles for which the authors have elected to pay a fee for publication as OA rather than as closed access.Bronze OA denotes articles that appear as OA after an embargo period of closed access or articles that appear available as OA despite lacking license information to guara

138、ntee OA in the long term.Green OA denotes articles that are self-archived by authors in OA repositories,which are often maintained,curated,and administered by universities or other institutions.The Hybrid and Bronze categories have been combined as Other Journal-Based OA in this report because of th

139、eir similar structure as journal-hosted types of OA that allow only conditionaland potentially revocableOA.The number of articles published annually in closed-access journals increased by 112%between 2003 and 2022(Figure PBS-8).Over the same period,annual publishing of Green OA articles increased by

140、 228%,while Other Journal-Based OA articles(Hybrid and Bronze OA)increased by 198%.Gold OA articles(which are published in OA journals with no restrictions)had the largest percentage growth,from 19,089 articles in 2003 to 991,805 articles in 2022,an increase of over 5,000%.Hence,although the majorit

141、y(77%)of S&E articles in 2003 whose access status is known were published in closed-access journals,fewer than half(49%)were in closed-access journals in 2022.National Science Board|Science&Engineering Indicators|NSB-2023-3324Publication yearNumber of articlesClosed accessGreen OAOther Journal-Based

142、 OAGold OA200320042005200620072008200920102011201220132014201520162017201820192020202120220500,0001,000,0001,500,0002,000,000Figure PBS-8S&E publications,by publication access type:200322OA=open access.Note(s):Articles refer to publications from a selection of conference proceedings and peer-reviewe

143、d journals in S&E fields from Scopus.Articles are classified by their year of publication.OA types are mutually exclusive.For articles published under multiple OA types,the article will be counted as part of only the first type it matches in this list:Gold OA,Other Journal-Based OA,or Green OA.Summi

144、ng all OA and closed-access article counts results in a smaller number of articles than for all S&E because the access status of some articles(e.g.,those without digital object identifiers)cannot be reliably ascertained.Greenarticles are published in toll-access journals but archived in an OA archiv

145、e,or repository.These repositories may be discipline specific(like arXiv)or institutional repositories operated by universities or other institutions.Green articles may be published versions or preprints and can have any license or no license.Bronze(Other Journal-Based OA)articles are free to read o

146、n the publishers website,without a license that grants any other rights.There may be a delay between publication and availability to read,and often articles can be removed unilaterally by the publisher.Hybrid(Other Journal-Based OA)articles are free to read at the time of publication,with an open li

147、cense.These are usually published in exchange for an article processing charge.Goldarticles have all the same characteristics as Hybrid articles but are published in all-OA journals,which are in turn called Gold journals or just OA journals.Source(s):National Center for Science and Engineering Stati

148、stics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsTo conclude this section,the findings of the output analysis reveal the growth in scientific publications over time,with upper-middle-income economies exhibiting particularly lar

149、ge percentage increases.Meanwhile,the distribution of publications across scientific fields shows that life sciences dominated in the United States,Europe,and Japan,whereas publications in engineering and computer sciences dominated in China and India.In OA,the dramatic growth of Gold OA publication

150、s and the steady growth of publications in other OA categories show an increased shift toward open science.However,OA can impede the dissemination of some scientific research.Publishing research as OA often requires authors to pay article processing fees,which may be prohibitive for scientists in le

151、ss-developed nations or whose funders do not subsidize those fees.4 The fees can be seen as shifting the costs of accessing research from readers and libraries to authors(Larivire and Sugimoto 2018).National Science Board|Science&Engineering Indicators|NSB-2023-3325Impact of Published ResearchAs a c

152、omplement to measures of the total production of articles published by U.S.-based researchers,indicators gauging the scientific significance of those articles aid in assessing the vitality and competitiveness of the U.S.S&E enterprise.A key assertion in the study of scientific communication is that

153、the author of a scientific journal article cites the previously published articles that influenced or informed the authors research(Merton 1973;Tahamtan and Bornmann 2018).Thus,when an article is referenced by many other articles,it is deemed to have exceptional scientific impact(Garfield 1973).Alte

154、rnate explanations for citation patterns exist,such as the belief that they are a mechanism for the citing author to bestow credit on an earlier author(Small 2004).These interpretations of citation patterns suggest that authors who produce highly cited articles have greater scientific influence than

155、 those who do not.By extension,nations whose authors produce a disproportionate share of the most highly cited articles in a given field are regarded as generating research results with greater impact.In general,most of the scientific articles published garner few or no citations,whereas for a small

156、 share,each article ends up with hundreds or thousands of citations(Van Noorden,Maher,and Nuzzo 2014).Recently published articles tend to have fewer citations than those published many years ago because articles are referenced only after they have been disseminated and read throughout the research c

157、ommunity.Counting the cumulative citations earned by an article at least 2 years after publication provides the means to normalize the measure of impact for a given year.This 2-year lag provides sufficient time for high-impact articles to attract attention and therefore receive a distinguishing numb

158、er of citations(Wang 2012).Those in the top 1%of the articles based on this measurement of citations are designated as highly cited articles(HCAs).Therefore,this report provides impact measures for articles up to those published in 2020,calculated using the citation counts for those articles at the

159、end of 2022.Note that some articles may receive a much higher share of their citations many years after publication(Ke et al.2015).A method of representing scientific impact at the national level calculates the share of a specific nations scientific output among the HCAs in a given year.To identify

160、the HCAs for each year,publications in each scientific field are ranked based on their accumulated citations,generating a list of the top 1%of that distribution.A separate list is generated for each field to account for differences in citation practices and patterns among the various disciplines(Sci

161、ence-Metrix 2021b).Aggregating the lists for all fields produces the HCA list;that list is the compilation of the top 1%of articles in each field by citations rather than the top 1%overall.Each article on the list is attributed to a nation if at least one author on the publication is affiliated with

162、 an institution located in that region,country,or economy(meaning that one article will be attributed to every nation represented among its coauthors).The estimate of scientific impact is based on the share of a specific region,country,or economys articles designated as HCAs.For a region,country,or

163、economy with impact on par with that of the entire global scientific community,1%of that region,country,or economys scientific articles would be found in the top 1%.An HCA share above 1.0 means that more than 1%of the nations articles achieved HCA status,indicating that the nations published researc

164、h has disproportionately more impact relative to the volume of articles its researchers produce.5 A consistent increase in a region,country,or economys HCA ratio over time suggests that its S&E enterprise is rising in stature as a producer of notable research findings.Impact by Region,Country,or Eco

165、nomyFor 2020,1.7%of U.S.scholarly publications with U.S.authors were on the HCA list,showing that the United States generates a disproportionate share of those articles(Figure PBS-9).The HCA share for the United States had stayed above 1.9%in each year from 2008 through 2016.The nations HCA share ha

166、s declined each year since 2014 and stands at its lowest level since 2006.National Science Board|Science&Engineering Indicators|NSB-2023-3326Publication yearPercent of articlesUnited StatesEU-27ChinaIndiaJapan2006200720082009201020112012201320142015201620172018201920200.000.501.001.502.00Figure PBS-

167、9S&E publications in the top 1%most-cited journal articles as a share of all S&E journal articles,by selected region,country,or economy:200620EU-27=European Union.Note(s):Articles refer to articles from peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publica

168、tion and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Citation data are based on all citations made to articles in their publication year and all following years and are normalized by subfield and publication year to a

169、llow for comparisons across subfields and over time,resulting in the world level standing at 1.00 for each subfield and year.A minimum 2-year citation window is needed for a highly cited article(HCA)score to be computed.This results in scores regarding HCA not being computed after 2020 because the c

170、itation window for more recent years is not yet complete.The share of articles in the top 1%is computed as follows:Sx=HCAx/Ax,where Sx is the share of output from country x in the top 1%most-cited articles;HCAx is the number of articles from country x that are among the top 1%of most-cited articles(

171、using full counting,with the exception of articles at the limit of the top 1%,which are fractioned so the world average can stand at 1%);and Ax is the total number of articles from country x with a relative citation score,which excludes articles released after 2020 and unclassified publications.The

172、world average is 1.00 for each year.For more details,see Table SPBS-70.See Table SPBS-1 for countries included in the EU;beginning in 2020,the United Kingdom was no longer a member of the EU.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and

173、citation database,accessed April 2023.Science and Engineering IndicatorsIn contrast,Chinas HCA share has increased in each of the past 15 years,rising from 0.4%in 2006 to 1.3%in 2020(Figure PBS-9).The disparity in HCA shares between the United States and China has decreased steadily since 2008.One f

174、actor that may affect this trend is the increase in the number of publications with U.S.and Chinese coauthors,discussed in the section International Collaboration Patterns.Any such articles in the 1%of the most highly cited publications in a given year would be credited toward the HCA shares of both

175、 countries.Given that on a whole-count basis,China produced more scientific articles than the United States in 2020,this convergence appears to represent a consistent increase in the scientific impact of publications with Chinese authors(Table SPBS-17).National Science Board|Science&Engineering Indi

176、cators|NSB-2023-3327Chinas HCA share in 2020 exceeded that of the EU-27 region for the first time(Figure PBS-9).The collective HCA share for the EU-27 has stayed at or above 1.2%since 2010.The HCA share of Japan,another major contributor to the worlds scientific literature,has tended to lag behind t

177、he overall global HCA share.Japans HCA share reached 1.0%in 2019 for the first time since at least 2006 and maintained that level in 2020.Indias HCA share matched the global HCA share in 2020 for the first time,reaching 1.0%.Note that scientists who publish predominantly in non-English-language jour

178、nals may receive lower citations in general because the language barrier could limit the readership of their articles in the international community(Di Bitetti and Ferreras 2016).Figure PBS-10 shows the field-specific HCA shares of the five regions,countries,or economies with the largest number of s

179、cientific publications in 2022,focusing on the fields representing the largest share of scientific articles in 2020(Table SPBS-3 through Table SPBS-16).This figure illustrates how national scientific impact varies by discipline.HCA shares by whole count for all regions,countries,and economies across

180、 all fields are provided in Table SPBS-72 through Table SPBS-85.National Science Board|Science&Engineering Indicators|NSB-2023-3328Region,country,or economyPercent of articlesHealth sciencesPhysicsComputer and information sciencesBiological and biomedical sciencesEngineeringChemistrySocial sciencesU

181、nited StatesChinaEU-27JapanIndia0.00.51.01.52.02.5Figure PBS-10S&E publications in the top 1%most-cited journal articles as a share of all journal articles for selected S&E fields,by selected region,country,or economy:2020EU-27=European Union.Note(s):Articles refer to articles from peer-reviewed jou

182、rnals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are allocated to a region or country on a whole count basis.Citation data a

183、re based on all citations made to articles in their publication year and all following years and are normalized by subfield and publication year to allow for comparisons across subfields and over time,resulting in the world level standing at 1.00 for each subfield and year.A minimum 2-year citation

184、window is needed for a highly cited article(HCA)score to be computed.This results in scores regarding HCA not being computed after 2020 because the citation window for more recent years is not yet complete.The share of articles in the top 1%is computed as follows:Sx=HCAx/Ax,where Sx is the share of

185、output from country x in the top 1%most-cited articles;HCAx is the number of articles from country x that are among the top 1%of most-cited articles(using full counting);and Ax is the total number of articles from country x with a relative citation score,which excludes articles released after 2020 a

186、nd unclassified publications.The world average is 1.00 for each year.For more details,see Table SPBS-70 through Table SPBS-84.See Table SPBS-1 for countries included in the EU;beginning in 2020,the United Kingdom was no longer a member of the EU.National Science Board|Science&Engineering Indicators|

187、NSB-2023-3329Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsIn the United States,physics had the highest share of publications in 2020 designated as HCAs(Figure PBS-1

188、0).Other fields in which the United States had a high HCA share were geosciences,atmospheric sciences,and ocean sciences and materials science(Table SPBS-77 and Table SPBS-79).Note that physics is not a dominant field in the United States in terms of number of publications(Figure PBS-5).For China,th

189、e social sciences had the highest share of articles designated as HCAs in 2020(Figure PBS-10),although that field accounts for a relatively small share of Chinas total publications(see Figure PBS-6).The EU-27 region demonstrated higher relative impact in articles in health sciences,as well as geosci

190、ences(Figure PBS-10;Table SPBS-77).In Japan,publications in the fields of astronomy and astrophysics,geosciences,and physics showed high HCA shares(Figure PBS-10;Table SPBS-72 and Table SPBS-77).India showed relatively higher impact in physics than in other fields and had particularly notable impact

191、 in astronomy and astrophysics(Figure PBS-10;Table SPBS-72).Impact and Open AccessAs discussed earlier,the share of scientific articles published as OA has increased dramatically since 2012(Figure PBS-8).Researchers have suggested that OA articles have a greater potential readership than articles pu

192、blished in closed-access journals and therefore are more likely to have higher citation rates.A recent review of such studies showed mixed evidence for that claim(Langham-Putrow et al.2021).Worldwide analysis of highly cited articles by publication access type also shows mixed results(Figure PBS-11)

193、.The share of articles published under closed access in the 1%of most highly cited articles per year fell from 1.1%in 2006 to 0.8%in 2020.The HCA share for Green OA journals stayed at or above 2%for most years since 2006.In contrast,the HCA share for combined Hybrid and Bronze OA journals(“Other Jou

194、rnal-Based OA”)rose from 1.5%in 2009 to 2%in 2020.As noted earlier,Gold OA journals now have the largest share of scientific publications by access type(Figure PBS-8).However,the HCA share for those journals has lagged behind that of the other categories for the past 15 years,staying in the 0.7%0.8%

195、range for most of that period.Significant publishers of Gold OA journals,such as the Multidisciplinary Digital Publishing Institute(MDPI),are increasing the number of articles published per year at a high rate,meaning that the number of articles required to meet the 1%HCA threshold is also growing r

196、apidly.6National Science Board|Science&Engineering Indicators|NSB-2023-3330Publication yearPercent of articlesClosed accessGreen OAOther Journal-Based OAGold OA2006200720082009201020112012201320142015201620172018201920200123Figure PBS-11S&E publications in the top 1%most-cited journal articles as a

197、share of all articles,by publication access type:200620OA=open access.Note(s):Articles refer to articles from peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional addres

198、s(es)of the author(s)listed in the article.Citation data are based on all citations made to articles in their publication year and all following years and are normalized by subfield and publication year to allow for comparisons across subfields and over time,resulting in the world level standing at

199、1.00 for each subfield and year.A minimum 2-year citation window is needed for a highly cited article(HCA)score to be computed.This results in scores regarding HCA not being computed after 2020 because the citation window for more recent years is not yet complete.The share of articles in the top 1%i

200、s computed as follows:Sx=HCAx/Ax,where Sx is the share of output from country x in the top 1%most-cited articles;HCAx is the number of articles from country x that are among the top 1%of most-cited articles(using full counting,with the exception of articles at the limit of the top 1%,which are fract

201、ioned so the world average can stand at 1%);and Ax is the total number of articles from country x with a relative citation score,which excludes articles released after 2020 and unclassified publications.The world average is 1.00 for each year.For more details,see Table SPBS-86 through Table SPBS-89.

202、Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsTo conclude this section,when looking at trends in the articles with the highest citation rates per year,the United Sta

203、tes produces articles that gain significant recognition after publishing at a disproportionate rate compared with global publications each year.In contrast,although Chinas annual article output exceeds that of the United States,Chinas articles are not as well represented among the most highly cited

204、articles.However,the impact of articles published by Chinese authors has seen significant annual increases since 2006;as of 2020,Chinas presence among the most highly cited articles exceeds that of the EU-27 and Japan.National Science Board|Science&Engineering Indicators|NSB-2023-3331International C

205、ollaboration and CitationsS&E research has become more global over the past decadea trend evidenced cross-nationally(Glnzel and Schubert 2005;Luukkonen et al.1993;Royal Society 2011).Researchers gather scientific expertise beyond their region,country,or economys borders through collaboration(coautho

206、ring articles)and citation(referencing articles from other regions,countries,or economies).Measured at the region,country,or economy level,international collaboration and citation are strongly influenced by the size and the policies of the region,country,or economy.For example,some regions,countries

207、,or economies provide preferential funding for cross-national research within a region through programs such as the European Commissions Horizon Europe(European Commission 2021).This section of the report examines trends in collaborations between researchersas measured by coauthorships and citations

208、particularly among those involving international connections.In the sidebar Artificial Intelligence Publication Output and International Collaboration,this section also explores international collaboration in greater depth in the field of artificial intelligence using network analysis.Researchers ma

209、y collaborate for several reasons,including to develop a scientific relationship with another researcher or to gain access to costly or shared equipment.They may also work together to meet conditions attached to research funding that require international collaboration(Wagner 2018).In general,nation

210、al governments encourage international collaboration to achieve outcomes that exceed what they could achieve individually(although they may perceive risks in collaborating with regions,countries,or economies they regard as a potential threat).These positive outcomes include training a robust S&E wor

211、kforce,partnering with researchers from developing countries,advancing domestic science excellence,increasing the impact of discoveries through better distribution of knowledge,strengthening scientific and diplomatic relations,and enhancing a sense of shared responsibility for future action(Lyons et

212、 al.2016).Also,international collaborations increase the impact of research,as measured by citations(Chinchilla-Rodrguez,Sugimoto,and Larivire 2019;Narin,Stevens,and Whitlow 1991;Sugimoto et al.2017).Domestic collaboration among researchers in the academic,government,and industry sectors also result

213、s in articles that receive higher citation rates when compared with articles from a single author or authors from only one sector(see the section Business Collaborations in Published Literature in Indicators 2022 report“2022 Invention,Knowledge Transfer,and Innovation”).International Collaboration P

214、atternsAn article is classified as an international collaboration if at least two author organizations are located in different regions,countries,or economies,as determined by their addresses on the article.In 2022,the United States contributed to the largest number of articles involving internation

215、al coauthorship(241,823 articles,representing 32%of all internationally coauthored articles)(Table SPBS-33).The most frequent coauthorship partners for the United States were China,the United Kingdom,Canada,and Germany(Table SPBS-35).In 2022,the global rate of international collaboration was 23%,but

216、 these rates varied by region,country,or economy.Researchers in the United States collaborated with international partners on 40%of their articles in 2022(Table SPBS-33).Of the top 15 largest producers,the regions,countries,or economies that had higher international collaboration rates than the Unit

217、ed States included the United Kingdom(67%),Australia(63%),France(60%),and Canada(60%).Conversely,regions,countries,or economies with rates of international collaboration lower than the U.S.rate included China(19%),India(24%),and Russia(25%)(Figure PBS-12).Beyond the 15 largest producers of publicati

218、ons,the 2022 international collaboration rates variedSaudi Arabia(80%),Switzerland(74%),and Belgium(73%)had higher collaboration rates than the United States,whereas Turkey(29%)and Brazil(38%)had lower collaboration rates,albeit still higher than those of China,India,and Russia(Table SPBS-33).7Natio

219、nal Science Board|Science&Engineering Indicators|NSB-2023-3332Region,country,or economyNumber of articlesInternational collaborationDomestic author(s)onlyChinaUnited StatesIndiaUnited KingdomGermanyItalyJapanCanadaFranceAustraliaSpainRussiaSouth KoreaBrazilIran0250,000500,000750,0001,000,000Figure P

220、BS-12International coauthorship of S&E publications for the 15 largest producing regions,countries,or economies of S&E publications:2022Note(s):Articles refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by th

221、eir year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a whole count basis(i.e.,each collaborating region,country,or economy is credited with one count).Articles without inter

222、national coauthorship are counts of articles with one or more institutional addresses all within a single region,country,or economy,which include single-author articles and articles coauthored under the same institutional address.International articles are articles with institutional addresses from

223、more than one region,country,or economy.The numbers of articles from the international collaboration and domestic author(s)only categories may not sum to the total article number because some coauthored publications have incomplete address information in the Scopus database.These publications often

224、cannot be reliably identified as international or domestic collaborations.For this reason,they are not included in either subcategory but are still counted toward the total number of articles.For more detail,see Table SPBS-37.Source(s):National Center for Science and Engineering Statistics;Science-M

225、etrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsThe percentage of worldwide S&E articles produced with international collaboration has grown over time,increasing from 19%in 2012 to 23%in 2022(Table SPBS-33).8 Each region,country,or economy l

226、eading in publications showed increases in international collaboration rates(Figure PBS-13).United Kingdom researchers had international coauthors on 37%of their articles in 2003,a percentage that had increased to 67%by 2022.Similarly,Germanys international collaboration rate increased from 39%to 56

227、%over the same period.The United States and Japan both saw notable increases in international collaborations between 2003 and 2022(from 23%to 40%and from 19%to 32%,respectively),whereas there was less change in the rates for China(from 15%to 19%)and India(from 19%to 24%).National Science Board|Scien

228、ce&Engineering Indicators|NSB-2023-3333YearPercent of articlesUnited KingdomGermanyUnited StatesJapanIndiaChina20032004200520062007200820092010201120122013201420152016201720182019202020212022020406080Figure PBS-13Selected leading region,countries,or economies with publications with international coa

229、uthors:200322Note(s):Articles refer to publications from a selection of journals and conference proceedings in S&E from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in t

230、he article.Articles are credited on a whole count basis(i.e.,each collaborating region,country,or economy is credited with one count).Articles with international institutions are counts of articles with institutional addresses from more than one region,country,or economy.For additional countries,see

231、 Table SPBS-33.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsOver time,the top collaborators of the United States have changed.In 2004,the United Kingdom accounted f

232、or 13%of articles that the United States coauthored internationallythe highest percentage of any partner region,country,or economy(Figure PBS-14).By 2022,China had become the largest collaborator with the United States,with 24%of internationally coauthored U.S.articles having a Chinese coauthor,alth

233、ough this represents a slight decline from 26%in 2020.Meanwhile,the percentage of U.S.internationally coauthored articles with the United Kingdom increased slightly over this period to 14%in 2022.National Science Board|Science&Engineering Indicators|NSB-2023-3334Publication yearPercent of articlesCh

234、inaUnited KingdomJapanSouth KoreaIndia2004200620082010201220142016201820202022051015202530Figure PBS-14U.S.international S&E publications with coauthor(s)from the United Kingdom and Asian countries:Selected years,200422Note(s):Articles refer to publications from a selection of conference proceedings

235、 and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a whole count basis(i.e.,each collabo

236、rating region,country,or economy is credited with one count).Articles with international institutions are counts of articles with institutional addresses from more than one region,country,or economy.For more detail,see Table SPBS-36.Source(s):National Center for Science and Engineering Statistics;Sc

237、ience-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsThe U.S.-China collaboration on publications has benefited not only both countries but also global science through the amount of published research collaborations,funding agency support

238、from the United States and China,and roles of collaborators on publications(Lee and Haupt 2020).The rapid growth in U.S.-China collaborations coincided with Chinas growing scientific and technological capabilities,such as rising R&D spending and university degree awards(see Indicators 2022 report“20

239、22 Higher Education in Science and Engineering”)both of which may be contributing factors to the U.S.-China collaboration pattern.Rates of U.S.collaboration with other Asian regions,countries,or economies have also changed over time.From 2004 to 2022,the percentage of U.S.internationally coauthored

240、articles with Japan decreased(from 9.1%to 5.3%),whereas the share coauthored with India increased(from 2.4%to 5.6%).The share of U.S.international collaborations involving South Korea grew between 2004 and 2012(from 4.5%to 5.6%),then declined through 2022(from 5.6%to 4.7%)as South Korea increased it

241、s partnerships with other Asian regions,countries,or economies(Figure PBS-14;Table SPBS-35).Meanwhile,there was little change from 2003 to 2022 in the U.S.coauthorship percentages with Canada(12%in 2022)and with European regions,countries,or economies such as the United Kingdom(14%in 2022)and German

242、y(11%in 2022)(Table SPBS-35).National Science Board|Science&Engineering Indicators|NSB-2023-3335Region,country,or economyRelative international collaboration index20032022CanadaSouth KoreaBrazilChinaSwitzerlandJapanNetherlandsGermanyUnited KingdomItalyFranceAustraliaSpainIndiaSaudi Arabia0.00.51.01.

243、5Normalizing international collaborations by a region,country,or economys publication output enables comparison independent of its size.For example,the international collaboration index(ICI),adapted from He(2009),is obtained by dividing a regions,countrys,or economys share of collaboration with a pa

244、rtner by the partners overall share of international collaborations with all regions,countries,or economies.An ICI value of 1.0 shows that the level of coauthorship between two regions,countries,or economies is proportional to the partners overall rates of international coauthorship.ICI values above

245、 1.0 indicate more extensive ties between two regions,countries,or economies,whereas values below 1.0 indicate weaker ties.In 2022,the United States had ICI values above 1.0 with Canada(1.3),South Korea(1.1),and Brazil(1.1).ICI values between the United States and most other major research-producing

246、 regions,countries,or economies increased between 2003 and 2022,except for South Korea(from 1.3 to 1.1),India(from 0.9 to 0.7),and Saudi Arabia(from 0.6 to 0.4)(Figure PBS-15).Figure PBS-15Relative international collaboration index of selected large-producing regions,countries,or economies with the

247、United States:2003 and 2022Note(s):Article counts for computing the index refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the

248、basis of the institutional address(es)of the author(s)listed in the article.Articles are credited on a whole count basis(i.e.,each collaborating region,country,or economy is credited with one count).Regions,countries,or economies that have contributed to less than 1%of all internationally coauthored

249、 articles in 2022 are omitted.The index of collaboration is calculated as follows:ICxy=(Cxy/Cx)/(Cy/Cw),where ICxy is the index of collaboration between country x and country y,Cxy is the number of publications coauthored between country x and country y,Cx is the total number of international coauth

250、orships by country x,Cy is the total number of international coauthorships by country y,and Cw is the total number of international coauthorships in the database.For additional regions,countries,or economies,see Table SPBS-38.Source(s):National Center for Science and Engineering Statistics;Science-M

251、etrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Board|Science&Engineering Indicators|NSB-2023-3336SIDEBAR ARTIFICIAL INTELLIGENCE PUBLICATION OUTPUT AND INTERNATIONAL COLLABORATIONArtificial Intelligence Publication Output a

252、nd International CollaborationThe National Science Board(NSB)highlighted the importance of international collaboration and work in technology-intensive industries in its Vision 2030 report(NSB 2020).This work became important because of the increasing globalization of science and engineering and the

253、 significance of research in fields such as artificial intelligence(AI)playing a large role“to empower U.S.business and entrepreneurs to succeed globally”(NSB 2020).The National Artificial Intelligence Research Resource Task Force(NAIRRTF)has also drawn special attention to the researchers behind AI

254、 during the fields rapid growth through a strategic plan to increase access to resources and training for diverse AI researchers(NAIRRTF 2023).Research in the field of AI is an important technology-intensive area that has grown rapidly in recent years and in which international collaborations are cr

255、ucial(Liu,Shapira,and Yue 2021).The nature of international partnerships between top-producing regions,countries,or economies,such as the United States and China,and other smaller,yet relatively important partnerships,such as Slovakia and Czechia,is an important influence on the AI advancements and

256、priority topics of study.The initial step to explore the state of international collaboration in the field of AI is determining the inclusion of articles from scientific journals and conference proceedings relevant for a network analysis of AI international collaboration.*Scopus has a series of clas

257、sification groups that help isolate relevant AI work;this subset of the Scopus data set was used to produce two network figures.The first represents the global collaboration network of AI and displays the number of coauthored articles between regions,countries,or economies to highlight the most prol

258、ific collaborations and collaborators.The second network focuses on the relative importance of collaborations by normalizing for overall publication output in AI.This helps highlight smaller,but relatively important,collaborative relationships.Together,the two figures allow for a more complete snaps

259、hot of the global collaboration network of AI.Figure PBS-B shows the network of AI research collaboration.The largest contributors from 2003 to 2022,in terms of total documents produced and the largest collaborative hubs,were China(274,096 total articles as a whole count)and the United States(133,60

260、1)(Table SPBS-91).Indeed,this country pairing was responsible for the most coauthored articles of any pair(13,631 articles)(Figure PBS-B).Further,of the top 10 most prolific pairs,all feature the United States or China.The first pairing that does not is the 11th most prolific pair of the United King

261、dom and Germany(2,166).Other important contributors in the network include Australia,Japan,Canada,and Singapore.The centrality of the United States and China may follow from their high publication output(see the section Output by Region,Country,or Economy),which enables a greater number of network c

262、onnections and echoes previously observed patterns of collaboration at the region,country,or economy level(Leydesdorff and Wagner 2008).National Science Board|Science&Engineering Indicators|NSB-2023-3337Figure PBS-BAI collaboration network,by region,country,or economy:20032022AI=artificial intellige

263、nce.National Science Board|Science&Engineering Indicators|NSB-2023-3338Note(s):This network diagram shows the number of cowritten articles by all pairs of regions,countries,or economies within the top 60 producers of AI-related research based on whole counting for those pairs that cowrote 400 articl

264、es or more.AI article counts refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus that were classified as AI in the All Science Journal Classification.Articles are classified by their year of publication and are assigned to a region,co

265、untry,or economy on the basis of the institutional address(es)of the author(s)listed in the article.Links are only shown in a single direction,dictated by alphabetical order.The size of the nodes is proportional to the total number of AI-related articles written by each region,country,or economy.The

266、 width of the links between nodes is proportional to the quantity of articles both regions,countries,or economies have cowritten.Positioning of nodes is defined using the Kamada-Kawai algorithm.For the list of regions,countries,and economies and their respective geographic regions in this figure,see

267、 Table SPBS-91.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsAlthough whole-counted documents produced by region,country,or economy pairs is an effective way to desc

268、ribe the overall hub-centered structure of collaboration in the field of AI,in Figure PBS-C,the focus on relationships relative to overall output highlights more regional collaboration patterns and partnerships.Instead of line thickness representing the number of coauthored documents,it now shows th

269、e index of collaboration.This index is best interpreted as the propensity of a region,country,or economy to collaborate with another,given their total collaborations.The baseline of this measure is equal to 1.00,where values greater than 1.00 show a preferential collaborative relationship.This helps

270、 highlight important relationships of regions,countries,or economies not significantly featured in Figure PBS-B.Specifically,the values of collaborative pairs Slovakia and Czechia(30.42),Serbia and Hungary(15.79),and the United Arab Emirates and Jordan(15.03)were notably large,given the number of co

271、authored publications that these countries produced.Unsurprisingly,geography and shared history play significant roles in these relationships,but they help illustrate smaller,and yet important,collaborative relationships in AI.National Science Board|Science&Engineering Indicators|NSB-2023-3339Figure

272、 PBS-CAI index of collaboration,by region,country,or economy pairs:20032022AI=artificial intelligence.National Science Board|Science&Engineering Indicators|NSB-2023-3340Note(s):The index of collaboration is calculated as follows:ICxy=(Cxy/Cx)/(Cy/Cw),where ICxy=index of collaboration between country

273、 x and country y,Cxy=number of publications coauthored between country x and country y in the relevant field,Cx=total number of international coauthorships by country x in the relevant field,Cy=total number of international coauthorships by country y in the relevant field,and Cw=total number of inte

274、rnational coauthorships in the relevant field overall.This network diagram shows indices of collaboration between all pairs of regions,countries,or economies within the top 60 producers of AI-related research,based on whole counting,for pairs having an index of collaboration higher than 1.00.AI arti

275、cles refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus that were classified as AI in the All Science Journal Classification.Articles are classified by their year of publication and are assigned to a region,country,or economy on the

276、basis of the institutional address(es)of the author(s)listed in the article.Links are only shown in a single direction,dictated by alphabetical order.The size of the nodes is proportional to the total number of AI-related articles written by each region,country,or economy.The width of the links betw

277、een nodes is proportional to the index of collaboration between both regions,countries,or economies.Positioning of nodes is defined using the Fruchterman-Reingold algorithm.For the list of regions,countries,and economies and their respective geographic regions in this figure,see Table SPBS-91.Source

278、(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsIn conclusion,looking at international collaboration in the field of AI through a network analysis provides some helpful conc

279、lusions about the current state of an increasingly important field.Although the United States and China were the most prominent actors in the global collaboration network,looking at relative relationships provides additional perspective for important partnerships like that of Slovakia and Czechia,wh

280、ich would be otherwise obscured.Going forward,AI research will likely remain an influential field affecting multiple facets of society in the coming years.The nature of the networks producing forthcoming research will be just as important in shaping new advancements as the international partnerships

281、 that produce them.*Network analysis refers to a broad range of visualization,mathematical,and statistical techniques centered around the conceptualization and depiction of entities and the relationships between them as nodes and edges(linkages between nodes).The analyses here are descriptive.Althou

282、gh these figures display work on AI specifically,they also show general trends in international collaboration.For example,the large collaboration between the United States and China is not unique to AI but is true for most subject areas.Further,the relative collaborative relationships and propensity

283、 scores are also likely true of other areas as they highlight geographically or culturally close ties where AI research is one part of the larger collaborative relationship.The focus on AI as an important area of study serves as a useful lens to look at these relationships and is not shared with the

284、 purpose of distinguishing AI networks from other fields of study.International Citation PatternsAnother indicator of international collaboration is cross-national citations,which are citations to a region,country,or economys publications that come from publications authored outside that region,coun

285、try,or economy.This section outlines an international citation measure called the relative citation index(RCI).The RCI is computed by dividing the share of the citing regions,countrys,or economys outgoing citations going to the cited region,country,or economy,then dividing this number by the share o

286、f publications attributed to the cited region,country,or economy.The measure is normalized by the publication output of each region,country,or economy.Otherwise,regions,countries,or economies such as the United States,the United Kingdom,Germany,and China would be favored,simply because they produce

287、so many articles and are therefore more likely to attract citations.Findings based on the RCI provide additional evidence of the globalization of S&E research.National Science Board|Science&Engineering Indicators|NSB-2023-3341An RCI value above 1.00 shows that the citation rate between two regions,c

288、ountries,or economies is higher than the baseline(and a value below 1.00 shows a citation rate lower than the baseline),taking into account their relative publication outputs.9 U.S.authors tended to cite English-speaking regions,countries,or economies disproportionately,with RCI values above 1.00 fo

289、r the United Kingdom(1.37),Canada(1.29),and Australia(1.07)(Table PBS-2).This finding may also be a function of the many scientific journals being published in English(Di Bitetti and Ferreras 2016).Some other notable European countries with high research activity had moderate RCI values based on cit

290、ations from the United States,such as Germany(0.96),France(0.93),and Italy(0.87).U.S.authors cite China(0.48),Iran(0.32),and India(0.25)less frequently than the baseline,given the number of articles produced by those countries.National Science Board|Science&Engineering Indicators|NSB-2023-3342Table

291、PBS-2Relative citation index for 15 largest producing regions,countries,or economies:2020(Index)Citing region,country,or economyCited region,country,or economyChinaUnited StatesIndiaUnited KingdomGermanyItalyJapanCanadaFranceAustraliaSpainRussiaSouth KoreaBrazilIranChina2.430.740.480.690.560.560.540

292、.690.540.950.520.130.960.320.73United States0.483.240.251.370.960.870.521.290.931.070.640.110.560.340.32India0.900.625.430.780.530.790.390.680.570.820.650.170.930.581.52United Kingdom0.521.340.356.521.191.150.511.291.141.600.910.130.540.420.41Germany0.461.270.261.656.801.200.621.051.311.060.920.210.

293、560.370.31Italy0.561.080.361.441.058.690.510.961.290.921.360.150.600.550.60Japan0.641.130.331.141.040.928.640.861.010.930.700.160.940.320.33Canada0.601.550.361.610.930.950.478.911.001.470.770.120.620.460.65France0.531.260.331.631.371.470.661.168.661.081.130.200.570.510.40Australia0.671.210.401.830.8

294、80.830.461.390.8211.020.770.110.630.450.61Spain0.581.030.421.491.041.780.481.041.211.168.840.160.630.750.66Russia0.610.750.500.900.961.010.550.700.910.730.7910.150.600.470.70South Korea1.020.970.630.890.740.840.760.840.670.950.670.148.990.380.78Brazil0.620.860.681.100.711.230.390.940.891.031.230.150

295、.5910.511.00Iran1.040.621.060.700.461.000.330.780.560.850.740.170.800.6311.93Note(s):Citations refer to publications from a selection of journals,books,and conference proceedings in S&E from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy o

296、n the basis of the institutional address(es)listed in the article.Articles are credited on a fractional count basis(i.e.,for articles with collaborating institutions from multiple regions,countries,or economies,each region,country,or economy receives fractional credit on the basis of the proportion

297、of its participating institutions).Citation counts are based on all citations made to articles in their publication year and in the following 2 years(i.e.,3-year citation window;scores in 2020 are based on citations to articles published in 2020 that were made in articles published in 202022).The re

298、lative citation index(RCI)normalizes cross-national citation data for variations in relative size of publication output.RCI is computed by dividing the share of the citing region,country,or economys outgoing citations attributed to the cited region,country,or economy,then dividing that amount by the

299、 share of publications attributed to the cited region,country,or economy.An RCI of 1.00 means that the citing region,country,or economy cites publications from the cited region,country,or economy as much as would be expected to happen randomly,showing no particular affinity between the regions,count

300、ries,or economies.Scores higher than 1.00 mean that the citing region,country,or economy has a higher-than-expected tendency to cite the cited region,country,or economys S&E literature.For more detail,see Table SPBS-39.Cells in which the region,country,or economy collaborates at or above the world a

301、verage for that year are shaded green.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering IndicatorsNational Science Board|Science&Engineering Indicators|NSB-2023-3343FieldRelative

302、citation indexAstronomy and astrophysicsPsychologyHealth sciencesBiological and biomedical sciencesSocial sciencesEngineeringMathematics and statisticsComputer and information sciencesPhysicsChemistryNatural resources and conservationAgricultural sciencesMaterials science01234567The RCI also provide

303、s a view into the international nature of the scientific research in each region,country,or economy by determining the number of other regions,countries,or economies from which the region,country,or economy draws its research(i.e.,citations).For example,authors from China predominantly cited article

304、s from China(2.43)and cite articles from only South Korea and Australia(among the leading publication producers)near the baseline rate(Table PBS-2).Iran(11.93)and Russia(10.15)tended to cite their own publications extensively.Conversely,France frequently cited research from numerous other regions,co

305、untries,or economies,such as the United Kingdom(1.63),Italy(1.47),Germany(1.37),and the United States(1.26).Many other European regions,countries,or economies displayed a similar pattern of extensive cross-national citations.RCI results at the scientific field level provide insights into the extent

306、to which regions,countries,or economies build on their own research within a given field rather than on research gleaned from elsewhere(Table SPBS-40 through Table SPBS-53).These results are thus a proxy measure for the degree to which researchers in a given field are insular or international in the

307、ir citation behavior.For example,in 2022,the United States had an overall domestic RCI of 3.24(Table PBS-2).This means that U.S.articles had more than three times as many citations to earlier U.S.publications than the baseline,given the number of these earlier U.S.publications.In materials science,t

308、he United States had a domestic RCI of 6.68 in 2022(Figure PBS-16),which means that there are more than six times as many citations to U.S.articles as the baseline.This suggests that U.S.materials science researchers built particularly extensively on earlier U.S.research.The same holds true in agric

309、ultural sciences(4.92),natural resources and conservation(4.86),and chemistry(4.60).Meanwhile,the United States had a lower domestic RCI in astronomy and astrophysics(1.89),psychology(2.00),and health sciences(2.37),suggesting that U.S.researchers in these fields had a relatively stronger connection

310、 to international research.That said,these RCIs remain above 1.00 because researchers tend to cite domestic publications disproportionately.Figure PBS-16U.S.domestic relative citation index across fields:2022National Science Board|Science&Engineering Indicators|NSB-2023-3344Note(s):Article counts fo

311、r computing the index refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus.Articles are classified by their year of publication and are assigned to a region,country,or economy on the basis of the institutional address(es)of the author(

312、s)listed in the article.Articles are credited on a whole count basis(i.e.,each collaborating region,country,or economy is credited with one count).Regions,countries,or economies that have contributed to less than 1%of all internationally coauthored articles in 2022 are omitted.The domestic relative

313、citation index is calculated as follows:ICxy=(Cxy/Cx)/(Cy/Cw),where ICxy is the index of collaboration between country x and country y,Cxy is the number of publications coauthored between country x and country y,Cx is the total number of international coauthorships by country x,Cy is the total numbe

314、r of international coauthorships by country y,and Cw is the total number of international coauthorships in the database.Source(s):National Center for Science and Engineering Statistics;Science-Metrix;Elsevier,Scopus abstract and citation database,accessed April 2023.Science and Engineering Indicator

315、sTo conclude this section,the findings from the analysis of international collaborations and citations reveal that regions,countries,or economies had wide variations in their propensity to collaborate with international partners,although all major regions,countries,or economies increased their colla

316、boration rate over time.Researchers in the United States collaborated increasingly with Asian partnersmost notably from China.Meanwhile,international citation patterns reveal that the United States disproportionately cited publications from established research communities,including its own,with its

317、 international connections varying widely across scientific fields.National Science Board|Science&Engineering Indicators|NSB-2023-3345ConclusionBased on the overall size of the U.S.contribution to S&E research publication output and its relative impact,as measured by citations to its S&E publication

318、s,the United States remains a highly influential nation.The publication outputs of the United States,Japan,the United Kingdom,and the EU-27 are concentrated in health sciences,whereas publications from China and India focused more on engineering and computer and information sciences,respectively.In

319、terms of S&E publication quantity,Chinas output has grown rapidly and is now nearly double that of the United States.In terms of impact among S&E publications,China has increased rapidly in the last decade.The high-income economies(including the United States,the EU-27,and Japan)have slowly increase

320、d their large base of S&E publications,whereas middle-income and upper-middle-income economies have rapidly increased their production,collaboration,and impact despite beginning from a smaller S&E publications base.International research collaboration is increasing,reflecting traditional ties across

321、 regions,countries,or economies and new relationships that stem from growing capabilities in the middle-income economies.Greater publication outputwith greater and more diverse collaborationsmeans more regions,countries,or economies are contributing,and many are doing so with U.S.authors.Finally,OA

322、articles showed considerable growth in terms of output and impact.The growth of open science should continue to impact the way research is produced,consumed,and cited in coming years.National Science Board|Science&Engineering Indicators|NSB-2023-3346GlossaryDefinitionsCitations:Citations,generally a

323、t the end of each article,provide researchers with the list of the prior research relied on for the article.Citations of S&E publications by other S&E publications provide an indication of the impact of publications and of the flow of knowledge or linkage between sectors or geographic locations.Coau

324、thorship:Coauthorship refers to cases in which more than one author is listed on a publication.Data on coauthorship can be used to measure collaboration across regions,countries,economies,and institutional sectors.Publication counts of coauthorship use whole counting,so each region,country,or econom

325、y contributing to the article receives credit for that article.An article is considered to contain an international coauthorship when institutional addresses for its authors are located in two or more different regions,countries,or economies.Table SPBS-36 shows international coauthorship from 2003 t

326、o 2022.European Union(EU-27):The EU comprises 27 member nations:Austria,Belgium,Bulgaria,Croatia,Cyprus,Czechia,Denmark,Estonia,Finland,France,Germany,Greece,Hungary,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,the Netherlands,Poland,Portugal,Romania,Slovakia,Slovenia,Spain,and Sweden.Bulgaria an

327、d Romania joined the EU in 2007,and Croatia joined in 2013these nations are included in the EU grouping for all years analyzed in this report.In 2020,the United Kingdom left the EU,and data covering the United Kingdom are excluded from the EU-27 in the text of the report but are available in the sup

328、plemental tables as“EU-27 and United Kingdom.”Fractional counting:A method of counting S&E publications in which credit for coauthored publications is divided among the collaborating institutions or regions,countries,or economies based on the proportion of their participating authors.Fractional coun

329、ting allocates the publication count based on the proportion of the coauthors named on the article with institutional addresses from each region,country,or economy.Fractional counting enables the counts to sum up to the number of total articles.For example,if a publication were authored by two resea

330、rchers from the University of Oslo,one from University College London,and one from the University of Washington,half of the publication would be attributed to Norway,and a quarter each to the United Kingdom and the United States when the fractions are calculated at the level of researchers.For this

331、report,fractions were calculated at the level of researchers.If an author provides multiple institutions,and those institutions are in different regions,countries,or economies,then each region,country,or economy receives an appropriate fraction of the count.Highly cited article(HCA):An HCA ratio pro

332、vides an indication of scientific impact(Waltman,van Eck,and Wouters 2013).The HCA ratio for a region,country,or economy is calculated as the share of all articles published in a given year by authors with institutional addresses within that region,country,or economy that fall within the top 1%by ci

333、tation count of all articles published that year,measured for each research field.The HCA ratio is indexed to 1.00,so a region,country,or economy whose authors produce highly cited articles at the expected(i.e.,global average)rate has an HCA ratio of 1.00 that is,1%of the regions,countrys,or economys articles are among the top 1%o